Alkenes

Introducing reactions of alkenes.

Addition of bromine to methylcyclohexene:

Steps:

1. Alkene C=C bond attacks bromine, forming a bromonium ion;
2. The bromonium ion is attacked by bromine anion from the back side according to the least-motion-principle, forming the product.

The reaction between vinylcyclopentane and hydrogen chloride:

Steps:

1. C=C bond is protonated to generate a secondary carbocation;
2. Neighboring alkyl groups migrate to form new carbocations (in two possibilities);
3. Chloride anion associates with carbocation to form the product.